The purpose of this study is to continue and expand upon the previous investigation of maternal addiction, by conducting a randomized, double-blinded, placebo controlled, crossover study of intranasal oxytocin on maternal brain responses. 150 mothers from the University of Iowa and the Yale Child Study Center will be enrolled (75 with a history of drug addiction and 75 matched control mothers), along with their 2 to 12-month-old infants, to participate in four study visits over a two-month period.